There are numerous such studies, some of which (e.g., later studies from Bengen that allow a higher initial safe withdrawal rate - SWR - due to diversifying beyond large-cap US stocks and US treasuries; and others, e.g., from Morningstar, that show a lower SWR due to high valuations).

In any case, Monte Carlo simulations that tested the original 4% rule concluded that it has an 87% chance of success in the future - for 30-year retirements. Early retirees have a far lower SWR because hitting $0 in Year 31 is a success for a 30-year retirement, but a failure for a 35-year one.